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A Well-Shod Porcupine

Here at the Porcupine Project, things are getting heavy. Or rather the latest drawing from Naval Architect Iver Franzen is of the heaviest part of Porcupine—the ballast keel. The hull came with some six-thousand pounds of internal lead in the bilges, but Porcupine will require about twice that much to safely ply Presque Isle Bay as a Schoolship. To maximize the effectiveness of this additional ballast, we’re applying a bit of STEM and putting it outside the hull.

Porcupine's "shoe" will run along the bottom of the keel, and counter balance the sail plan

Porcupine’s “shoe” will run along the bottom of the keel, and counter balance the sail plan

The idea of external ballast is well established—from classic yachts to modern racers, iron and lead keels have become the norm for over a hundred years because they’re far more effective. The lower the weight, the further it is from the effort in the rig, and the “stiffer” the vessel becomes. When Porcupine’s 1813 namesake was built, however, the common practice was to load ballast into the bilges. Often this was stone, ideally cut into stackable squares or rectangles that minimize air gaps. Built in the wilderness that was early 19th-Century Erie, the original Porcupine may well have carried a ballast load of local rocks.

Our new Porcupine will have a “shoe” instead. Not as dagger shaped as modern fin-style keels, the shoe is essentially a one foot deep extension of steel and lead along the bottom of her existing full-length keel. Except for the fact that it’s bolted instead of nailed, it’s not unlike a horseshoe, hence the name. And while the drawing of it is sequentially fourth in the set of plans that will make Porcupine, the shoe will be the first thing we install as we, quite literally, transform our schooner from the bottom up.

All best,

Jamie Trost, Team Porcupine, and the BMC Staff

2 Responses

  1. Bob Kerber

    Jamie, I love following the Porcupine as it’s built. Keep the postings coming!!

  2. […] I first wrote about the ballast keel, there’s been a fair bit of head-scratching about the best way to secure it to the hull. But with […]

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